Is this a bug in iota?

[Ali Çehreli]

On 04/18/2012 08:45 PM, Brad Anderson wrote:
 > On Thursday, 19 April 2012 at 03:37:00 UTC, bearophile wrote:
 >> Brad Anderson:
 >>> You can popFront() for as long as you want well passed the length.
 >>> Obviously popping off the front of a zero length range isn't valid
 >>> but I would have expected a range violation to occur rather than it
 >>> to silently continuing the series with a wrapped around length.

I agree. I think it is just an oversight in iota()'s general 
implementation because its floating point specialization does have an 
assert check in popFront():

import std.range;

void main()
{
     auto r = iota(1.0); // <-- note 'double' type
     r.popFront();
     r.popFront();       // <-- assertion failure
}

 >> I think it's a matter of design and it's a matter of having an
 >> alternative Phobos release that contains asserts too. Adding the test
 >> slows down something (iota) that must be as fast as possible. And
 >> currently asserts are removed from the compiled Phobos...
 >>
 >> Bye,
 >> bearophile
 >
 > Since iota is a template doesn't that mean it's not in phobos.lib but
 > rather generated and built into my application? I'm not compiling in
 > release mode so I would think any bounds checking it had would remain (I
 > haven't yet looked at the source to see if there are any checks). I can
 > definitely see stripping any bounds checking from a release build, of
 > course.

I think this warrants an enhancement request. Thank you. :)

 >
 > Doing this same thing to a slice of an array does throw a Range
 > Violation exception in release (and asserts in debug).
 >
 > Regards,
 > Brad Anderson

Ali